Metamorphism, Metamorphic Processes, And Metamorphic Products

Question 1

The process of change or transformation of a pre-existing rock, in solid state, into another due to heat, pressure, and chemically active fluids.

Answer 1

Metamorphism

Question 2

A form of metamorphism due to hydrothermal fluids exchanging constituents with an external source.

Answer 2

Metasomatism

Question 3

Increase in temperature and pressure.

Answer 3

Prograde Metamorphism

Question 4

Decrease in temperature and pressure.

Answer 4

Retrograde Metamorphism

Question 5

Metamorphism that affects areas with less than 100 square kilometers.

Answer 5

Local Metamorphism

Question 6

Metamorphism that affects areas greater than 100 square kilometers.

Answer 6

Regional Metamorphism

Question 7

Also known as “Protoliths”, are the original rocks from where the produced metamorphic rocks transformed from.

Answer 7

Parent Rocks

Question 8

The type of metamorphic rock that will be produced can also depend on what their ________ is.

Answer 8

Protolith

Question 9

Agent of Metamorphism that provides energy for chemical reactions and recrystallization of minerals.

Answer 9

Heat

Question 10

Agent of Metamorphism that provides stress in equal directions or varying amounts in different directions.

Answer 10

Pressure

Question 11

Agent of Metamorphism that provides and enhances mobility of ions present.

Answer 11

Chemically Active Fluids

Question 12

Give the temperature range, pressure range, and depth range for LOW GRADE metamorphism.

Answer 12

Temperature: 200-300 Degrees Celcius
Pressure: 300-600 MegaPascals
Depth: 0-6 kilometres

Question 13

Give the temperature range, pressure range, and depth range for INTERMEDIATE GRADE metamorphism.

Answer 13

Temperature: 300-500 Degrees Celsius
Pressure: 600-1000 MegaPascals
Depth: 2-20 Kilometeres

Question 14

Give the temperature range, pressure range, and depth range for HIGH GRADE metamorphism.

Answer 14

Temperature: >500 Degrees Celsius
Pressure: >1000 MegaPascals
Depth: >20 Kilometres

Question 15

Type of pressure that is also called as confining pressure, is a uniform or isotropic form of pressure, where pressure is equal in all directions, which usually produces equant grains and non-foliated texture of metamorphic rocks.

Answer 15

Hydrostatic Pressure

Question 16

Hydrostatic pressure is also called as?

Answer 16

Confining Pressure

Question 17

Is also called as the burying stress, is a non-uniform or anistropic form of pressure, where pressure in unequal in all directions, which usually produces inequant grains in all directions and foliated texture of metamorphic rocks.

Answer 17

Lithostatic Stress

Question 18

Lithostatic stress is also called as?

Answer 18

Burying Pressure

Question 19

A variable temperature, low pressure metamorphism that develops locally where hot magma intrudes relatively cold, upper crustal country rock.

Answer 19

Contact Metamorphism

Question 20

Products of Contact Metamorphism.

Answer 20

Hornfels, Metaquartzite, and Skarn

Question 21

Type of metamorphism characterized by chemical alteration from circulating fluids within cracks and fissures. Pervasive at ocean spreading ridges that experience tension, thinning, and uplift, causes metasomatism.

Answer 21

Hydrothermal Metamorphism

Question 22

Products of Hydrothermal Metamorphism.

Answer 22

Alteration Products and Metallic Ore Deposits

Question 23

Given the major minerals and description, what is the type?

Major Minerals: Albite, Paragonite (Na-rich Mica)

Description: High temperature alteration resulting in Na enrichment.

Answer 23

Albitic

Question 24

Given the major minerals and description, what is the type?

Major Minerals: Alunite and Sulfate Minerals

Description: Occurs in hot spring environments and gold-copper pophyry deposits by oxidation of sulfate minerals.

Answer 24

Alunitic

Question 25

Given the major minerals and description, what is the type? Major Minerals: Kaolinite, Smectite, Illite Description: Low temperature decomposition of feldspars in acidic conditions and occurs in gold deposits hosted by sedimentary rocks.

Answer 25

Argillic

Question 26

Given the major minerals and description, what is the type? Major Minerals: Carbonate Minerals: Calcite, Dolomite and Ankerite, and accessory minerals: Chlorite, Sericite, and Albite. Description: Replacement by Carbonate Minerals at variable temperatures.

Answer 26

Carbonitization

Question 27

Given the major minerals and description, what is the type? Major Minerals: Sericite, Quartz, and Pyrite Description: Decomposition of silicic rocks and is associated with porphyry copper deposits.

Answer 27

Phyllic

Question 28

Given the major minerals and description, what is the type? Major Minerals: Biotite, Potassium Felspar, and Adularia Description: High temperature alteration in silicic magma, resulting in K enrichment, and commonly underlies phyllic zones.

Answer 28

Potassic

Question 29

Given the major minerals and description, what is the type? Major Minerals: Chlorite, Epidote, Actinolite, and Tremolite Description: Low to moderate temperature decomposition of basic and ultrabasic rocks enriched in pyroxene and amphibole, biotite and plagioclase, and also occurs in gold-copper porphyry deposits.

Answer 29

Propylitic

Question 30

Given the major minerals and description, what is the type? Major Minerals: Sericite Description: Alteration of feldspars.

Answer 30

Sericitic

Question 31

Given the major minerals and description, what is the type? Major Minerals: Serpentine and Talc Description: Low temperature alteration of basic and ultrabasic rocks.

Answer 31

Serpentinization

Question 32

Given the major minerals and description, what is the type? Major Minerals: Quartz and Chert Description: Replacement by silica minerals at variable temperatures.

Answer 32

Silication

Question 33

Given the major minerals and description, what is the type? Major Minerals: Albite Description: Low temperature alteration of Ca-plagioclase to Albite

Answer 33

Spilitization

Question 34

Given the major minerals and description, what is the type? Major Minerals: Zeolite Minerals Description: Low temperature replacement of glass in volcanic rocks.

Answer 34

Zeolitic

Question 35

Term for fine-grained mica minerals.

Answer 35

Sericite

Question 36

A regional metamorphism induced by increase in pressure and temperature with non-uniform stress, which produces foliated textures, mostly aerially extensive, and dominates convergent margins and associated fold and thrust belts.

Answer 36

Dynamothermal Metamorphism

Question 37

Products of Dynamothermal Metamorphism.

Answer 37

Greenschist, Amphibolite, Granulite, Blueschist, and Eclogite

Question 38

Metamorphism that results from increase in lithostatic stress caused by deep burial of rocks and produces non-foliated textures, affects regional subsiding basins that accumulate thick sequences of sediments and volcanic debris, and usually starts at 300 Degrees Celsius and gradational with diagenesis at depths of about 8 Kilometres.

Answer 38

Burial Metamorphism

Question 39

Products of Burial Metamorphism.

Answer 39

Non-foliated rocks with low temperature mineral assemblages.

Question 40

A local form of metamorphism generated by explosive volcanic eruptions or relatively rare collisions of extraterrestrial objects with Earth, causong a high strain rate.

Answer 40

Impact Metamorphism

Question 41

Producs of impact metamorphism.

Answer 41

Impactites, Breccias, Shocked Quarts Lamellae, Pseudotachylites, Coesite, and Stishovite

Question 42

Induced primarily by non-uniform stress in fault zones and shear zones, where the high strain rate is mostly local but extend to a regional scale in large faults or shear zones, and most likely occur in the same fault or shear zone.

Answer 42

Dynamic Metamorphism

Question 43

Products of Dynamic Metamorphism.

Answer 43

Cataclasites, Pseudotachylites, and Mylonites

Question 44

Given the temperature, pressure, depth, and products, identify which kind of metamorphism is induced. Temperature: High Pressure/Depth: Low pressures at shallow depths (0-6 Kilometres) Products: Non-foliated, fine-grained; Hornfels

Answer 44

Contact

Question 45

Given the temperature, pressure, depth, and products, identify which kind of metamorphism is induced. Temperature: High Pressure/Depth: Moderate pressures Products: Mg-Fe rich Hydrous Minerals

Answer 45

Hydrothermal

Question 46

Given the temperature, pressure, depth, and products, identify which kind of metamorphism is induced. Temperature: Moderate Pressure/Depth: High pressures over an extensive area at considerable depths (5-20 Kilometres, sometimes >30 Kilometres). Products: High-grade, foliated metamorphic rocks

Answer 46

Dynamothermal

Question 47

Given the temperature, pressure, depth, and products, identify which kind of metamorphism is induced. Temperature: Varying Pressure/Depth: Varying Pressures and Depth Products: Non-foliated Metamorphic Rocks

Answer 47

Burial

Question 48

Given the temperature, pressure, depth, and products, identify which kind of metamorphism is induced. Temperature: Very High Pressure/Depth: Very High Pressures at Shallow Depths Products: High-pressure polymorphs of minerals.

Answer 48

Impact

Question 49

A low temperature, brittle grain-fracturing process that involves grain size reduction through mechanical grinding, rotation and crushing of rock.

Answer 49

Cataclasis

Question 50

A fine-grained, non-foliated, clastic metamorphic rock produced by cataclastic processes.

Answer 50

Cataclasite

Question 51

A ductile grain reduction process that produces oriented grains of smaller diameter.

Answer 51

Mylonitization

Question 52

A product of mylonitization characterized by grain size reduction via macroscopic scale cataclasis, plastic stretching, and thinning associated with ductile deformation.

Answer 52

Mylonite

Question 53

Occurs in metamorphic rocks where individual atoms or molecules can migrate in gaseous, liquid, or solid phases from one location in a rock body to a new location.

Answer 53

Diffusion

Question 54

Involves the dissolution of solid grains under high compressive stress conditions.

Answer 54

Pressolution

Question 55

An insoluble seam that accumulates as soluble minerals dissolve.

Answer 55

Stylolite

Question 56

Occurs when existing minerals are transformed under higher temperature and/or pressure conditions, without experiencing a significant change in chemical composition.

Answer 56

Recrystallization

Question 57

The nucleation and growth of new minerals as pre-existing minerals become unstable due to temperature or pressure changes.

Answer 57

Neocrystallization

Question 58

Newly formed minerals that are ditinctly larger than the minerals in the surrounding matrix.

Answer 58

Pophyroblasts

Question 59

The segregation of minerals in an initially homogenous rock due to different physical or chemical characteristics, such as solubility, ductility, mineral growth, or crystallization temperature.

Answer 59

Differentiation

Question 60

Partially melted rocks that form by quenching under high strain rates in shear zone fractures.

Answer 60

Pseudotachylites

Question 61

A metamorphic halo in the contact zone that surrounds it, produced from the head of the igneous intrusion, and can range from centimeters to hundreds of meters in diameter.

Answer 61

Aureole

Question 62

Regional metamorphism is usually associated to?

Answer 62

Covergent and Divergent Plate Boundaries